Okay, guy, thanks. More from the white house and Jon Karl is traveling with the president at Martha's vineyard this morning and, Jon, the president first heard about this on his way back to Martha's vineyard from the white house. Reporter: That's right, George. This went item to the president. He was briefed aboard air force one on his way to Martha's vineyard shortly after the video went online and, George, this comes just after the president had congratulated U.S. Troops on some of the heaviest bombardment we have seen on Isis targets in Iraq that for the first time forced them to retreat and give up territory that it has gained. But the white house has until now downplayed the threat that Isis plays, the immediate threat, to American targets saying that they are focused in the region but, George, this video suggests that this battle may have entered a new and more dangerous phase and perhaps the most disturbing part was that -- or one of the pose disturbing that executioner spoke fluent English with a british accent, a suggestion that there are people that can blend in with the west there as part of Isis. That is the big concern. The british prime minister David Cameron returning to 10 downing treat to deal with it and the president warned this fight against Isis is going to take a long time. Reporter: He sure has. He said that there is no end date on this in terms of U.S. Military involvement in Iraq and the battle against this group will be a long one. Okay, Jon Karl, thanks very much. It will be a long one.

This transcript has been automatically generated and may not be 100% accurate.

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